The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus for controlling a quantity of current supplied to both a thermal fixing unit and a light source for irradiating an original.
In general, image recording apparatus of this type comprises a light source for irradiating an original, an exposing unit for exposing a photosensitive recording medium to light, a transferring unit for transferring the image on the photosensitive recording medium to an image forming sheet, and a thermal fixing unit for thermally fixing the transferred image on the image forming sheet.
Conventionally, in the image recording apparatus of this type, the heater in the thermal fixing unit and the light source are controlled independently of each other. When the temperature of the heater in the thermal fixing unit drops below a predetermined temperature, the current is supplied to the heater in the thermal fixing unit in order to keep the heater at fixed temperature even during lighting of the light source. On the other hand, even if the current is being supplied to the heater in the thermal fixing unit, exposure may be carried out and the light source is lit. However, in the recording apparatus in which employed is a so-called transfer type photosensitive recording medium as described in U.S. Pat. No. 4,399,209 and Japanese Pat. application Kokai No. 58-88739, a large quantity of light is required to irradiate the original because the photosensitive recording medium is poor in photosensitivity. Therefore, it is obliged to employ the light source which consumes a large amount of electric power. Further, the heat source which consumes a large amount of electric power is also required in the thermal fixing unit. In case of supplying the current to both the light source and the heat source simultaneously, the total consumed current which is the sum of the currents supplied to the light source and the heat source exceeds a predetermined quantity, for example, 15 amperes, a household plug socket thus cannot be used.